1. Field of the Invention
The present invention relates to a cap device and, in particular, to a cap device which includes a cap that can be removed easily by a one-handed operation from an engagement portion on a main body such as that of a writing implement, paint applicator, make-up applicator, or container.
2. Description of the Related Art
A cap fitted onto a main body, such as that of a writing implement, paint applicator, make-up applicator, or container, can be separated therefrom by pulling it away from an engagement portion. With an article having a main body containing a liquid which would cause problems if it were to dry out, such as an applicator (correction pen) containing correcting ink, it often happens that the solvent within the correcting ink evaporates from the applicator tip so that the correcting ink accommodated within the main body solidifies, making it unusable. To prevent this, means, such as an inner cap, is provided within the cap to maintain a hermetic seal around the applicator tip. Also, the cap engages with the engagement portion of the main body with a comparatively strong engagement force. With this type of cap, it is necessary to use both hands to pull the cap from the engagement portion of the main body, and thus it is difficult to separate the cap from the main body by a one-handed operation.
"Device for Causing Cap To Spring Off Pen", disclosed in Japanese Utility Model Application Laid-Open No. 48-18239, and "Capped Container", disclosed in Japanese Patent Application Laid-Open No. 61-259962, are known means of pulling a cap from an engagement portion of a main body by a one-handed operation. However, these prior-art techniques do not relate to the present application in which the cap itself is of a configuration whereby the cap can be separated easily from the engagement portion of the main body by a one-handed operation. In the former prior-art technique, a pressure member is inserted between the cap and the pen shaft. To operate this pressure member, it is necessary to provide a handle portion of a fairly large surface area in such a manner that it is exposed to the exterior, which makes it impossible to obtain a product with an attractive design.
In addition, if the handle portion is made larger so as to make it easy to operate, a problem arises in that the handle portion is obstructive when the pen shaft is held during writing or the application of liquid.
In the latter prior-art technique, a sliding member that touches an aperture end surface of the inner cap is provided on the main body side, with the arrangement being such that the sliding member is pushed in a protruding direction by a spring. However, this prior-art technique necessitates modification of the engagement portion of the container itself, creating a problem in that it makes it impossible to utilize the mechanism that has long been known in the art for engagement between a cap and a main body such as that of a writing implement, paint applicator, make-up applicator, or container.
It is therefore an object of the present invention to solve the above described problems which are inherent in the prior-art technology and provide a cap device in which the implementation of a simple process on the cap alone makes it possible to pull the cap away from an engagement portion on a main body such as that of a writing implement, paint applicator, make-up applicator, or container by a one-handed operation.